Electron discharge tube



May 9, 1950 G. BEZY ELECTRON DISCHARGE TUBE Filed May 14, 1947 INVENTOR:

GEOR 658 BE ZY Patented May 9 1950 UNITED PATENT .ELEGTRUN DIS coi' Application May-14, 19457 fierial; 74?.932 In France Aprjl- 11,;1941

invention relates to electron discharge tubes and more particularly to; tubes'of the. kind utilizing an electrode or anpassembly of le trodes employed to act as; a mirror-reflecting the whole .orpart of. astream of electrons or charged particles in the tube.

The inventionis illustrated in and explained in connection with the accompanying drawing inwhich:

Figure 1 is a theoretical diagramshowingar- .rangements heretofore known ;-for purposes of showing. the differentiation therefrom of rny invention; Fig. 2a is a diagrammatic--illustration showing in sideview on e embodiment pf, my invention; Fig. 2b is a diagrammatic illustration in front view of the embodiment of,-my invention shownin Fig. 2a; Fig.3 a theoreticaland diagrammatic view showing the application-py y invention to cylindrical, circular or parabolic reflector electrodes; and Fig. l illustrates .in

.diagrammatic arrangement the application of .my invention to an i-ndirectly heated cathode systemv associated with a positive anodefor ,ac-

celerating the electrons.

Referring to Figure 1 which shows a typical ,from which electrons emitted, for example; by an ,electron gun, C are reflected. Thissurface which is, planar in ,Fig. 1 though-it might tonexample be spherical if the electrode .gA were spherical constitutes a mirror of fixed focal length and given radius.

The invention provides a reflector arrangement comprising essentially a simple electrode, that is planar, which is easy to construct, but which may be arranged to present the qualities of a mirror of any desired shape and which will permit any desired particular focal length to be obtained by control by electrical means.

Fig. 2a shows diagrammatically in side view and Fig. 2b in front view one embodiment of the invention. The references employed in Figs. 2a and 2b correspond to those in Fig. 1.

In Fig 2 electrode B is as before positive in relation to the electron gun C and accelerates the electrons towards the reflector electrode A which, as shown consists of a plurality of parts, in the v, w-ires or strips 1-, 2

-A composedpf several insulated pieces -2 ,maintained at voltages the el wrist-15m term of concentric ringa strips or wires, I ,".2 .3, .4, 15 which are electrically insulated from one another. and are maintained at different desired .-.potentials,lower than that of electrode B, by a potentiometer .P 7 By varying the voltages Y1,

Va-Va V4,'V5 applied to the parts L2. 3,}. is. possible to make the equipotential surfaceproduced of almost any desired shape-so that it may constitute a vconvex or concave mirror or (if vall the volta esareeoual) .a planar mirror. With ,appl -iedrvoltages as indicatedin Fig. 2a the mir- :ror.;-is;c oncave-, the voltagesibeingl successivlyfdecreasing outwardly of the central part 5.

he ;-i;nvention is equally applicable {to tyra- I dr1ca1,..circular, parabolic or reflector electrodes.

F t. -..zrpres t :exa nn ae enti emeboli-ct ele'ctrodeAconstituted y insulatedl a 1181 '5 adaptedfto be polarized from tapson a potentiometerP Mirrors in accordance with'thi invention can .be utilized to reflect planepencils obtained 'by suitable electron concentration arrangements associated with the cathode. W

-A similar arrangement can also be applied to concentrate-the discharge from afcathode. 1 in Fig. 4-. for egainpla 'q is an indirectly heated ,cath'odeand B;a.positiye anodev for accler ing the electrons. Around the cathode is an 3and so on circularly s urrounding the cathode emitted-from G are concentrated on the center of the anode B. I I The invention obviously enables manufacturing errors in electrode construction to f be compen- ;sated ;for in uselby applying s'uitable electrical correction potentials to the parts of the frefictor electrode...

The invention is especially applicable to v ry short wave generator tubes, of the kind in which part of a velocity modulated electron current is caused to return towards the cathode. However, the invention is also of general application, for example, to electron multipliers, oscillographs and the like.

Modulation of the return or reflected pencil of electrons can, if desired, be produced by introducing a modulation voltage at the terminals of the potentiometer P which feeds the different parts constituting the reflector electrode.

What I claim is:

1. Electric discharge apparatus comprising a source of charged particles, an electrode connected with a potential accelerating these particles, a. flat electrode connected with a potential which is negative in relation to the preceding, electrode for the purpose of producing between these two electrodes an equipotential surface reflecting th particles, and means associated with the said flat electrode for varying the form of the said equipotential surface.

2. Electric discharge apparatus comprising a source of charged particles, an electrode co'ncles, a flat electrod divided into a plurality of insulated concentric rings, and means for applying to the different rings potentials which are negative in relation to the first of the above-mentioned electrodes, these potentials being gradually variable toward the center of the flat electrode for the purpose of obtaining between the two electrodes a curved equipotential surface for the reflection of the particles.

4. Electric discharge apparatus comprising a source of charged particles, an electrode con nected with a potential accelerating these particles, a flat electrode divided into a plurality of insulated parallel bands, and means for applying to the different bands potentials which are'negative in relation to the first of the above-mentioned electrodes, these potentials being gradually variable toward the center of the flat electrode for the purpose of obtaining between the two electrodes a curved equipotential surface for the reflection of the particles.

5. Electric discharge apparatus comprising a Source of charged particles, an electrode permeable to these particles and connected with a positive potential in relation to the source,'a flat electrode disposed on the trajector of the particles after their passage through the permeable electrode and connected with a negative potential in relation to this permeable electrode for the purpos of producing between these two electrodes an equipotential surface for the reflection of the particles, and means associated with the said flat electrode for varying'the form of the said equipotential surface.

I 6. Electric discharge apparatus comprising a source of charged particles, an electrode connected with a potential accelerating these particles, a flat electrode disposed in the vicinity of the source and connected with a negative potential inrelation to the preceding electrode for the purpose of producing between these two electrodes an equipotential surface for the reflection of the particles emitted by the source toward the said accelerating electrode, and means associated with the said flat electrode for varying the form of the said equipotential surface.

7. Electric discharge apparatus comprising a source of charged particles, an electrode connected with a potential accelerating these particles, a flat electrode connected with a negative potential in relation to the preceding electrode for the purpose of producing between these two electrodes an equipotential surface reflecting the particles, means associated with the said flat V electrode for varying the form of the said equipotential surface, and means superposed to the said form-varying means for imparting a modulation to the flow of particles.

8. Electric discharge apparatus comprising a source of charged particles, an electrode connected with a potential accelerating these particles, 'a flat electrode divided into a plurality of insulated portions, and means for applying to these portions individual potentials which are negative in relation to the first of the abovementioned electrodes, for the purpose of giving a predetermined form to the equipotential surface of reflection of the particles produced between the two electrodes.

9. Electric discharge apparatus comprising a source of charged particles, an electrode c0nnected with a potential accelerating these particles, a flat electrode divided into a plurality of insulated portions, means for applying to these portions individual potentials which are negative in relation to the first of the above-mentioned electrodes, for the purpose of giving a predetermined form to the equipotential surface of reflection of the particles produced between the two electrodes, and means for applying to these portions potentials variable at the rhythm of modulation for the'purpose of modulating the flow of particles reflected by the equipotential surface.

GEORGES BEZY.

REFERENCES CITED The following references are of record in the l file of this vpatent:

- UNITED STATES PATENTS 

